Ed Klein's biography of President Barack Obama, The Amateur, has topped bestseller list of the New York Times, whose book reviewers would not touch it with a ten foot pole, for eleven weeks now, a legitimate cultural phenomenon on the scale of "50 Shades of Gray" that has outsold David Maraniss' well-received tome by a 7-1 margin.

The secret of Klein's success, he says, is simply his journalistic integrity.

"I think what makes the book special for this campaign season is that it has broken a lot of fresh news that has been relevant politically to the campaign," Klein said in an interview with BuzzFeed this week.

The book is "supported not simply by my opinions but by my reporting," Klein said. "It's telling people things they didn’t know before. As Rupert Murdoch said, this is a book that everyone should read."

And although Klein's credibility remains at a low ebb after a salacious biography of Hillary Clinton whose claims included the suggestion that her daughter was conceived by rape, the author's formula does in fact rest up on his posture as a mainstream journalist. It is an irony that despite a decades-long campaign against the Times in particular and the mainstream media in general, conservatives are hungry for a credentialed New York journalist with a suit and a ('70s vintage) Times Magazine editorship who tells them what they want to hear.

Klein's is one of the savviest career reinventions in American journalism, and The Amateur is his breakthrough, and it gives a reportorial, sober-minded platform to the kind of murmurs that have characterized the three years of the Obama presidency. The core theme, that Obama is fundamentally both an extreme left-winger and utterly out of his depth, is one that has been the focus of any number of quickie books by radio talk show hosts and of at least one meaty, reported assault by a movement conservative journalist, Stanley Kurtz's Radical-In-Chief.

But it's Klein's book that has won endorsement from the likes of Murdoch and Dick Cheney, who was impressed by Klein's credentials. "One of the things that’s been most enlightening for me is to read this new book that’s out that is — deals with this whole question of competence, and written by Ed Klein, used to be with the New York Times. It’s called 'The Amateur,'" Cheney said on Sean Hannity's show on Sunday.

Klein also had one bit of reporting that broke through a broader conversation, a tape-recorded interview with Rev. Jeremiah Wright in which Wright claimed that an Obama friend, Eric Whittaker, offered to buy his silence for $150,000. (A version of the story had in fact appeared earlier, in David Remnick's The Bridge, but drawn little attention at the time.

Other elements of Klein's reporting have not broken through the bubble of Fox News and talk radio.

"We’re in the middle of a presidential campaign and the left wing and the Obama campaign has made an effort to discredit the book because it's been so successful," Klein said. "I think the book has actually been quite well received by most people who have an open mind."

A more important shadow over his work may be part because the doubts about his Clinton book, whose unsubstantiated allegations of lesbianism and rape drew her circle to dismiss it as "trash."

Another anecdote that raised eyebrows was one about Bill Clinton urging Hillary to quit her job as Secretary of State and run against Obama this year.

"As far as the Bill Clinton material, after the book came out my sources inside the Clinton camp told me that Hillary was convinced that I got all that material from Chelsea of all people," Klein said, adding that Chelsea Clinton was not in fact his source.

"Chelsea is known by the Clintons to love to text her friends about what's going on inside her family politically. And it was a confirmation that Hillary understood that what I reported was true," Klein said. (Little of his Clinton reporting has found independent corroboration.)

Much of the mainstream coverage of Klein's book has focused on the improbability of certain anecdotes; for example, an excerpt that ran in the New York Post that described a falling-out between Michelle Obama and Oprah Winfrey.

"Oprah Winfrey has not denied anything that I’ve written about her in this book," Klein said.

As for the Huffington Post's claim that Klein lifted quotes from an article of theirs (an interview with Dr. David Scheiner): "That’s simply not true."

Klein has not yet decided whether to do another book on Obama if he wins a second term, he said.

And the mainstream challenges to Klein's credibility haven't prevented Klein from making the rounds to promote it in interviews that invariably begin with his mainstream credentials, and in which he dwells on the rigor of his reporting. He's appeared on Lou Dobbs' show, Sean Hannity's, Larry Kudlow's, and has done "literally several hundred radio shows," he said.

"I stand by every single quote," Klein said. "I don't feel that any of these charges have ever stuck."

Rosie Gray is a reporter for BuzzFeed News and is based in Washington, D.C. Gray reports on politics and foreign policy.